Bistatic SAR Data Focusing Using a Frequency Scaling Algorithm Based on an Analytical Spectrum in Tandem Configuration

A bistatic Frequency Scaling (FS) algorithm is proposed based on an exact analytical bistatic Point Target (PT) spectrum obtained with a Geometry-based Bistatic Formula (GBF) method in TanDEM configuration. Since numerical calculation is no longer needed when calculating the important parameter- the Half Quasi Bistatic Angle (HQBA), fast imaging process is achieved. Unlike the existing algorithms, it avoids the influence of the baseline to range ratio because of its precise spectrum. Therefore, the method can handle the bistatic data with a large baseline (even in extreme conditions). The proposed method is proved using simulated data. By comparing the experimental results between the proposed method and the numerical calculation method which has a heavy computational burden, the images were almost the same, which further proves the advantages and correctness of the proposed method.